/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.gossip.crdt;
/**
 * 
 * Immutable type 
 *
 * @param <SetType>
 * @param <MergeReturnType>
 */
public interface Crdt<SetType, MergeReturnType extends Crdt<SetType, MergeReturnType>> {

 
  MergeReturnType merge(MergeReturnType other);
  SetType value();
  /**
   * Called to self optimize. Some CRDTs may use some mechanism to clean up be 
   * removing obsolete data outside the scope of merging. IE this could clean up 
   * temporal values, old copies etc. 
   * @return the Crdt structure optimized 
   */
  MergeReturnType optimize();

}
